improve blpapi-wrapper logging with log levels

Refactored logging to properly distinguish between debug and trace level
logging.
use TypeScript anonymous functions and minor cleanup

During the converstion to TypeScript, there was a missed '() => {}'
style anonymous function.  Also a resolved // TODO comment was removed
due to being resolved.
refactor operations into private methods

This change is in preparation for supporting subscriptions.  The
generation of the next correlator id has been refactored into a
independent method as well as the code required to open a service.
echo an extra newline in example/ex1.sh

At the end of the example, the extra newlines ensure that your command
prompt displays properly.